Headspace solvent microextraction-gas chromatographic thermionic specific detector determination of amitraz in honey after hydrolysis to 2,4-dimethylaniline

A novel headspace solvent microextraction (HSME) method for the extraction of trace amounts of 2,4-dimethylaniline (2,4-DMA), produced after hydrolysis of amitraz, is presented. The hydrolysis reaction and HSME were carried out in a single step, and then the preconcentrated 2,4-DMA was analyzed gas chromatographically using a thermionic specific detector (TSD). Different parameters affecting the HSME procedure including the type of solvent, headspace volume, stirring rate, Na2SO4 content, solution and microdrop temperature, drop volume and extraction time were studied and optimized. The optimized conditions were 25 min solution equilibrium time, 10 min solvent equilibrium time, 5 mL headspace volume, 600 rpm stirring rate, 15% Na2SO4, solution temperature 60 °C, microdrop temperature 4 °C and microdrop volume 3 μL. The limit of detection (LOD) and limit of quantification (LOQ) of the method were 10 and 30 ngamitraz g−1honey, respectively, and the dynamic linear range was from 0.03 to 10 μgamitraz g−1honey. Finally, the proposed method was applied to the quantification of amitraz in spiked honey samples. Because of performing hydrolysis and extraction processes in a single step, the method provided a rapid, simple and sensitive approach to analysis of amitraz.